Control mechanism for multiple hydraulic gears



Oct. l2, 1937.

CONTROL MECHANISM FOB MULTIPLE HYDRAULIC GEARS Figi.

W. LENZ Filed July 29. 1935 Walter` Lenz,

@y www@ His Attrngj "'wanisms for multiple hydraulic ge lor torqueconverters such as are speeds and a reverse I: tiple hydraulic gedrawing.

, ing a vehicle.

A UNITED STATES PATENT CONTROL MEomimsM FOR MLTIPLE HYDRAULIC Ganas #Thepresent invention relates to Walter Lenz,

Berlin,

OFFICE Germany, assignor to General Electric Company, a corporation ofNew York Application July 29,

. 3 Claims.

control mechars, couplings used for operat- .ing vehicles in forward andreverse direction.

Morefspecically the inven of drives which have at ahead. operatingpositions The object of myV For a consideration of tion relates to thekind least two forward or or shifts for different position.

what I believe to be novel and my invention,` attention is directed tothe following descripti ed thereto in connecti In the draw `agrammatican operating positio Fig.'1.

The arrangement draulic gear or torqu on and the claims appendon withthe accompanying ns ofcertain parts of comprises a multiple hyeconverter unit I0 including two turbo typek torque converters ortransmitters II and I2 such as Oil, water or like liquid is draulictorque converter II and discharged therefrom and discharged therefromThe operating uid for t may be used for driv- Operating iiuid which maybe conducted to the hythrough a channel I3 through a channel I4.conducted to the hythrough a channel I5 through a channel I6. he twoconverters is .contained in a pan I1 secured to the bottom of the commoncasing for th e two converters. The

:duid is forced from the pan I1 into either of the converters by theaction of a pump I8 and the flow of fluid to the converters iscontrolled by a converter I l, and Fig. 3 i which fluid is conducted t othe'converter I2 and Aat the same time discharged from theoonvertjer II.

The valve I9 is controlled inaccordance with my invention by a specialservo-motor 20. This motor comprises a cylinder which has a portion 2Iof larger inner d smaller inner diameter.

iameter-and a. portion 22 of Two separate pistons ,1935,V l In GermanyAugu larger in diameter and the piston 24 smaller. Due to thev diiferentpiston diameters a smaller pressure is necessary for actuating or movingthe piston 23 than the piston 24. The piston 24, which has the smallerdiameter, is connected to one end of a rod 25, the other end of which isprovided with a toothed rack 26 meshing with a segmental gear 2l securedto the valve I9 so that movement of the piston 24 causes turningmovement of the rack 2l and accordingly of the valve I9. 'I'heservo-motor forms three control cham-A bers, a chamber 28 at theleft-hand end adjacent the piston 23, a chamber 29 at the right-hand endadjacent the piston 24, and an intermediate chamber 30 between the twopistons 23 and 24. The piston 23, as shown in the drawing, has an axialextension 3| with abore 32 and the piston 24 has a projection 33 whichforms in substance a continuation of the stem 25. This projection isguided inthe bore 32 of the piston 3| to maintain alignment of the twopistons. Actuating fluid is supplied to and discharged from the chambers28, 29, and 30 by means including conduits 34, 35, and 33 respectively.All ofthese conduits receive a fromaJ container 3l and discharge the uidto a suitable point, for instance the atmosphere, througha conduity38.The displacement of fluid in the different chambers is controlled byvalves 39,40,V and 4I respectively. These valves rhave stems secured toelectromagnets 42, 43, and 44 respectively. The energizing coils of theelectromagnets are connected to a switch 45 .having a lever 46. Thearrangement in Fig. lis shown in the neutral or stop position. In thiscase the lever 46 closes electric circuits to energize electromagnets 42and 43 from a suitable source of electric. energy 4'I.` Energlzing ofthe electromagnets 42 and 43 causes opening of the corresponding valves39, so that actuating fluid ctuating fluid under pressure" 31 to thechambers 28 and 29 respectively. The two pistons 23 and 24 thereby areforced into a central positidn forming a stopfor the piston 24, movementof the piston 23 towards the right being" limited by the cylinder I9 instop or neutral position permits the discharge of actuating fluid fromboth torque converters. To start operation the lever 46 is turnedclockwise or counterclockwise into one of the positions converter Il,depending upon whether ahead or reverse operation is desired. Thiscauses at :first positioning of a, coupling, not shown, in forward orreverse position through the piston 23 in this position wall. As statedbefore, the valve fluid to the converter II.

' electromagnet 43 is the conductors 4I and 49 respectively. The le ver46 when moved into ahead position causes de-energization of theelectromagnets 42 and 43 and simultaneously energization of theelectromagnet 44 whereby the valves 39 and 40 are closed and the valve4I is opened. This effects the discharge of fluid from the. chambers 28and 29 and the supply of fluid under pressure into the intermediatechamber 30, resulting in outward movement of the two pistons into theposition shown in Fig. 2. been turned to permit the supply of operatingWhen the lever 46 is in forward position it is left in this positionuntil a certain speed has been reached, usually half the full speed atwhich the converter II reaches the limit of its best efficiency. Toincrease the speed, the lever 46 is turned furtherin clockwise directioninto the position converter I2. In this position the circuits for theelectromagnets 42, #i4 are interrupted and the circuit for the closed.This effects closing of the valves 39 and 4| and opening of the valve40. The actuating fluid, such as air, then contained in the chamber 30is discharged to atmosphere,` whereas actuating medium is suppliedthrough the valve 40 and the conduit 35 to the control chamber 29. Thepiston 24 then is forced towards the left against the piston 23 untilboth pistons reach the end position, shown ln Fig. 3, in which theleft-hand face of the piston 23 engages a stop 50 secured to thecylinder cover. Under this condition the valve I9 has been turnedby therack 26 and the segmental gear 21 into a position in which actuatingfluid is supplied through the channel I5 to the converter I2 anddischarged from the converter Il through the channels I3 and I4. When itis desired to reduce the speed of the vehicle driven by the converters,the lever 46 is turned in counter-clockwise direction from the position"converter I2 to the ahead position converter II whereby the servo-motor2li and the valve I9 are moved from the position shown in Fig. 3 intothat shown in Fig. 2.

Having described the method of operation of my invention. together withthe apparatus which Inow consider to represent the best embodimentthereof, I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

'the cylinder end wall in which the valve I9 has 1. A servo-motor foroperating a plurality of hydraulic torque converters comprising acylinder, two separate pistons movably disposed in the cylinder anddefining a chamber between them, a projection with an axial dead endbore on one piston facing the other piston, the piston rod for the therpiston projecting on one side through and ontheother side into the deadend bore to maintaina'lignment of the two pistons and means forconducting actuating fluid to the chamber and to the ends of thecylinder.

2. A hydraulic torque converter arrangement comprising two converters,means for supplying and controlling the supply of operating fluid to theconverters, said means comprising a valve arranged to permit in acertain position the discharge of fluid from both converters and inother positions the supply of fluid to one converter and the dischargeof fluid from the other converter, and a control mechanism for the valvecomprising a servo-motor having a cylinder, two independent pistons ofdifferent diameters disposed in the cylinder, means including a rodconnecting the smaller of the pistons to the valve, a source ofactuating fluid under pressure, means for conducting and controlling theflow of fluid under pressure to the ends and to an intermediate portionof the cylinder and auxiliary means for maintaining alignment of thepistons, said auxiliary means comprising a projection with an axial deadend bore on the larger piston adjacent the smaller piston and anextension of said rod projecting into and having sliding fit with saidbore.

3. Aservo-.motor comprising a cylinder having a first portion with alarge bore and a second portion with a small bore, a first piston oflarge diameter disposed in the first portion, a second piston of smalldiameter disposed in the second portion, means limiting movement of thesecond piston and maintaining alignment of the two pistons comprising aprojection on the rst piston having an axial dead end bore and a rodconnected to the second piston and having an extension with a slidingfit in said bore, an intermediate portion of said projection having asliding fit with the wall of the second cylinder portion, and means forconducting fluid to and discharging fluid from the three spaces definedby the -pistons and the cylinder.

WALTER LENZ.

